Dignāga
... Among Dignaga's works there is Hetucakra (The wheel of reason), considered his first work on formal logic, advancing a new form of deductive reasoning ... It may be regarded as a bridge between the older doctrine of trairūpya and Dignaga's own later theory of vyāpti which is a concept related to the Western notion of implication ... Among Dignaga's works there is Hetucakra (The wheel of reason), considered his first work on formal logic, advancing a new form of deductive reasoning ...